I want to implement a "10 day trial status" on my application. I found this post that was made back in 2009 (I like the 3rd methos). Has anything changed in this area since 2009? Is there a better way?
Post link...
Creating an Android trial application that expires after a fixed time period
thanks, Gary
The best way to do this would be to set up a MySQL database on your server and store the time and date of the installation and the device ID in it. So every time the user opens your app you check with your server how long the device is already running the app. You could do this or if you don't want to get involved in server side programming you could just create a local SQLite database and do the same(then of corse you won't have to save the device ID). However this is not so safe because the user can access your database if his/her device is rooted. Therefore if you're choosing this way I'd recommend using SQLCipher for Android. It encrypts your database.
Related
I'm new to app dev...
I read somewhere in the doc: "...In most cases you want to use SharedPreferences as it is automatically backed up and migrated to new devices..."
On first install my app saves a few settings with SharedPreferences. It works great but if I uninstall the app or install it on another device the preference settings are lost.
How can I have these settings saved online within google somehow to be able to retrieve them if the user changes his phone or similar...
Could someone point me in the right direction ?
I read somewhere in the doc: "...In most cases you want to use SharedPreferences as it is automatically backed up and migrated to new devices..."
Your words "backed up and migrated to new devices" is nowhere written nor its true.
We use SharedPreferences in order to minimise the database operations, its like keeping variables handy.
On first install my app saves a few settings with SharedPreferences. It works great but if I uninstall the app or install it on another device the preference settings are lost.
If you wants to store or remember the device dependent settings, use device id / imei_id and store it on your web server mysql database
Even if user uninstalls app from the device and installs again anytime in future, make a call with async task to server by sending deviceid / imei_id and fetch its settings from mysql database and show it.
How can I have these settings saved online within google somehow to be
able to retrieve them if the user changes his phone or similar...
If user changes device, you can do nothing.
One way is, keep public device_id levels keys on server.
If user changes device and uses that key, then show him a response, this key is assigned to another device, but if you are the same, wait for our support
Call him, confirm he is the same old user with new device and delete his old entry from mysql and assign old key to the new device entry
Or use OTP SMS system to identify already existing customers with unique phone numbers
If OTP authentication code is correct then fetch settings for that user from the server, delete old mysql entry, modify new entry with old key and mobile number
This should be the your direction
Edit : 2 ##
I was hoping an easier solution exist but....
There is no short cuts for developers till the date, and it will be never.
Why, no short cuts / easy ways ?
Any device ( mobile, desktop / laptop / any AI device ) which is operated by a system software, is able to perform the tasks as per it is structured.
Ex : android is java based, obviously you can Make javascript based apps, but it is the extensions to the existing system, Android still has the base of Java virtual machine. ( Dalvic / Malvic like )
So, it is always better to use native java
Yes, Kotlin is best option now a days and better than hybrid approach
Every way has its own advantages, disadvantages
If you are developer, should go with native approach
Now your java code never knows, which version it is running on, so you have to, check android versions programming wise, and decide the flow for above Marshmallow & below marshmallow too, and it is explicitly done by developer by coding.
Ex, once user registers, he never shown please register again screen, it is not the magic, nor google, nor, java, nor android does anything, developer has decided, planned, architectured, designed, coded, tested that.
Even developers needs to take care of exceptions, you need to handle it in order to save your app from crashing.
In short developer is god, who creates his own universe, and everything is pre-planned and verified thats it.
You should use allowBackup = "true" in your manifest file. More details can be found here: AutoBackup
I have a situation where admin has defined both English and Spanish Language at the admin panel. Right now, Whatever the changes he made in admin panel, it is reflecting on the website.
My question that when we have different platforms like Android and iOS, Whatever the changes he made in the Admin panel I want it to reflect in the Android as well. As of now, I have defined both language information in Strings.xml.
I do not think calling server each time for the Labels is a good idea. If i do, it might slow down the app.
In detail, i have a validation message like "Please Enter User Name". And the admin changed the label in the back-end and made it Enter User Name. Each time calling server to get the information is bad idea. I would like to save the information or data for certain periods. say 2 hours or 24 hours.
What is the best way to achieve this?
In my opinion the best solution is to keep it in sqlite. You should check version of strings by calling your API when i.e. application is starting and then update its if necessary.
Unfortunatell queries SQLITE every time when user open new activity/fragment might also slow down your app. In my opinion you should keep your map of string in Application Class or in Object (if you use kotlin) - query your sqlite after checking version of your string or when app is starting if API is unavailable.
So basically I have made a few small apps in the past, but this is my first 'proper' app.
One of the main features of the app, and the bit that I am struggling with is that I need to be able to populate a ListView with all of the other users logged into the app, however I only want to display users that are within a set distance, for example 10 meters.
I tried using Bluetooth to achieve this, however that didn't work. I would now like to use location services to do this.
My idea is to have to app send the location of the device to an external server every few minutes and then all other devices can run a function that compare their location to others found on this server.
Does anybody know how I could go about achieving this, or know of any tutorials that cover a simpler topic. Thank you
Disclaimer: I'm not an android developer, but this seems like a design issue not a implementation issue so hopefully my comments below might be of some use...
I don't think there's an API that you can just set to "true" to get this functionality, so I think you're going to have to custom craft all the moving parts (and there are a couple). I would think the general process would be something like:
On the client:
User on client logs in to server with some sort of identity (i.e. "user#gmail.com")
Every X minutes the client app gets the current location (i.e. "100N 90E") and sends it up to a server
Every X minutes the client polls the server to see who is within 10 miles (i.e."joe#gmail.com", "mary#gmail.com")
On the server:
Needs some sort of authentication endpoints for getting a user's identity
Needs an endpoint for users to register their location ("user#gmail.com is at 100N 90E")
Needs a service to find out how far each user is from each other
Needs an endpoint to return the users within X miles (list generated from #3)
Each one of these steps shouldn't be difficult on their own and you can actually get pretty nuts with the distribution algorithm on server step #3 if you wanted to.
Some questions you can ask yourself are:
"How do I set up a server to listen for HTTP requests?" - Take a look into Node.JS for a simple solution
"How do I get a user's location in android?" - Easy google search finds plenty of documentation
"How do I write a service to continuously perform actions?" - Node.JS would again help with this
"Where will I store user's locations and their distances from each other?" - You can look into a NoSQL option like CouchBase or MongoDb. Or you could use MySQL for a more structured database.
Hope this helps...
This question already has answers here:
Creating an Android trial application that expires after a fixed time period
(13 answers)
Closed 9 years ago.
My android application should work only for 1 month after its release. What to do for that?
Please see this question, it has a good answer.
I will give you my experience with trials. At first I tried just using the date on the phone, but then realized if they uninstall and re-install this can be bypassed. This could be fixed by storing the install date somewhere on the file system (hidden), but what happens if the user wipes data or finds the file?
I also tried to just check the date/time at a server anywhere (maybe your www site?), but this imposes restrictions on your application because they must have internet. Soon I realized the need for better license management, so the last solution was used.
The last solution would be to setup a server. You can use the device's unique ID (whichever you choose - I went with the Bluetooth MAC ID because my application requires bluetooth as well), post to a server to check if the user has a trial, if they don't I issue them one, if they do I check the expiration. Now I have complete control over when trials expire. Since my application is a business app that is used in the field, this is very handy if a potential buyer needs another week.
The only issue with the last solution is that if you plan on publishing to Market, you must use their payment system.
Good luck!
Just to add a bit more code-related as well:
Use SharedPreferences to store the date on first-start up
Get the date at every start up - you can use for exampe Date.currentTimeMillis() - and calculate if 1 month has passed
Check current date and calculate expiration date.
That should be pretty easy, just read the date on the first start-up and store it, then compare the date for every subsequent start-up with the stored date, if its greater that x days, pop-up a message box saying the app has expired.
Or am I missing something ?
/Tony
Use alarm Reciever instead, and broadcast when it gets expired.
http://developer.android.com/reference/android/app/AlarmManager.html,
here is a tutorial TOO.. http://moazzam-khan.com/blog/?p=157
if you are worried about the data on the device(and you should! unless you encrypt it) you can save the data on a server and retrieve it on each start up.
On the other hand if application crackers worries you, dalvik byte code today is easily reversed using dedexter or smali and with apktools and jarsigner you can actually find the place where the protection is change some jumps, fill the rest of the code with nops to keep it aligned and resign it uploading it to some crackers market where they share it. So it wont help you too much.
You can make life hard for them if you obfuscate your code with proguard, but it will slow them down,wont stop them.
If your app is web based, meaning the user will need to obtain server data from you, create a key for the registered users that will be received from the server (you can base it on their private details + IMEI) and verify your requests with it, if you get wrong\no key from the client reject the request.
It's not 100% proof either since requests could be faked and someone could grab someone else's IMEI and key and face all the requests.
welcome to broken software copy protection world :-)
I have an application that uses the SQLiteDatabase as its database, because each application has its own, custom database (well, custom values), for another app I am making, I want to hose a single SQLiteDatabase that every app will access, for example one app adds a row, while another then reads it at a later time.
Is there anyway to do this? Everything I've found has left me believing there is not, but there has to be.
Any ideas?
Update:
I'm not sure if you've quite understood what I'm trying to do, sorry. The apps accessing this db are all the "same" app, but from different phones, for example, the database could be used to store a user id and their favorite color, so another phone could search their user id, and get the color in db with that user id –
I'm sorry if I did not make that clear enough
Of course there is way to do it! There is always a way!
Anywho, what I think you are looking for is a remote server. These can be done in a few way depending on how much money you have.
(1)If you're broke like me all the time, then you can make an extra computer you have at home act as a server for your app. This can cause a few ( :) hehe few) security issues for your home though. Also you will have a lot of traffic on your home network.
(2)Another option it's to get a domain name and web host. Most of the web hosting services I have seen offer database support. So what you could do is hop on, create your database on the web host server then link your app to your server. The cost on that varies based on your needs.
Really though, is your app interfacing with mulitple people? I can't think of a reason you would want this feature on any other phone (device) than your (relative to us customers) device. I rarely hand my device over to others, and never unless it's locked.
SQLite is serverless. In a situation as described there are no guarantees that it will work properly. Your solution is to create a database server that will cater to multiply Android clients simultaneously.
For more information on SQLite see LinuxForu.com and/or SQLite.org